The present inventions relates to devices known variously as traversing machines, actuators, motors, positioning devices, robots, etc. More particularly, the invention relates to such devices that rotate an operating stage and move it linearly along an axis of rotation.
Various kinds of robotic actuators are known that provide multiple degrees of freedom. There is a need in the field for actuators that provide high accuracy, low weight, large load-carrying capacity, compact size, smooth operation, and cost-effectiveness. One known type of actuator that provides two-degrees of freedom, which scores highly in terms of the above design goals, is an entire class of so-called X-Y traversing systems, for example, as described in U.S. Pat. No. 5,334,892, the entirety of which is incorporated herein by reference. This patent describes a traversing system with a movable stage supported on an air bearing above a planar base. The traversing system described in the patent is, however, limited to movement in a plane.